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VM 100 vs 120

R

Raif Harik

Joined
Jan 14, 2020
Messages
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Location
Austin, TX
My question is actually this: is a 120 ever really necessary? It seems from references in posts and utube videos that the 120 is way more common.
I've turned some pretty big crazy pieces with my 100. I have a 24" swing. I don't turn bowls that big really. (I'd kind of like to but can't imagine what someone would do with a 24 inch bowl) But I've never once thought oh this chuck may be a bit small. Jaws maybe. But I got a set of 4" jaws and can't imagine using much bigger.
It seems to me that the only advantage of the larger chuck is that it can probably take bigger jaws but unless you are doing really large crazy pieces when would you need jaws that large? Further if you are turning crazy large pieces you are probably drilling down a face plate.
 
Is a chuck itself ever really necessary? One could probably make do with a faceplate only if he had to (and I'm told people did for a long time before my time), but where's the tool collecting fun in that? 😎

On a serious note, if you look at the chart at the end of this manual, it lists all of the jaws available for the VM100 and the VM120. One of my favorites is the 110 shark jaws, which is a size that is not available on the VM100, and I use my 5" jaws quite often for large platters, and have had a couple where I thought, you know it wouldn't be bad to have a 6".

 
Interesting. So the 110 does take a 5" jaw. As I mentioned I have the 4" ones. I have only made a couple large platters ( 14" or so. maybe that's not that large ). What is the advantage of larger tenon on platters? I probably had so many problems on mine that the jaw size didn't even rank 🙂
 
I have both, I have 3 sizes of shark jaws on the 100's, 4" and 5" dovetail and 130mm shark jaws on the 120's. I use the 100's for 80% of the work I do, but on 16"-20" platters and bowls, I love the larger jaws.
 
I've wondered about the question the other way around, ie, why is a 100 necessary? I've never had a problem with the 120 being too big to hold small work. The 150 OTOH is kind of a pain, mainly because of the dual action closing mechanism that I mistakenly activate pretty much every single time, especially while balancing a heavy blank. The bigger chucks all use the same jaws, the jaws from the 100 aren't transferrable as far as I know. I'm not adding incompatible jaw sets to the pile on the bench at this point. I don't know if you can get the 100 with a direct thread, if I were to buy another chuck I'd definitely opt to skip the insert (I really do need at least one or two more!).
 
I think the perspective of the chuck manufacturers has to be remembered. When I bought a Jet 1014 mini in '97 or '98, I called Oneway to talk about their chucks. At that time it was the big geared Stronghold, or the smaller tommy bar chuck, which really was a chuck style best suited for people with three hands (or a stout spindle lock). They said if I could wait another month or two, their new smaller, made-for-minis chuck, the Talon, would be available. Talon it was.

From their engineering standpoint, an 8 pound chuck on a small lathe is unnecessary and steals away power used for cutting. A 3.5 pound chuck holding a large piece of wood on a large lathe may be overstressing the design capacity of the smaller chuck. I don't know what the engineering thresholds of the different size chucks may be, but... the right tool for the job is sage advise.
 
I think you have good point using the smaller chuck. With 4 inch jaws you should be able to turn 12" to 14" bowls. I would say jaws 4" or smaller use the smaller chuck. I thought it was ridiculous when I bought my 140 the stock jaws start at about 2" . I have 4 chucks 2 large, and 2 small, I keep a set of 9" and 5" on the large chucks, with 4" and 2" on the smaller ones. When I turn a 20" bowl I use the 9" jaws. I rarely use a faceplate.
 
One place for a larger chuck would be coring, where bigger jaws give you a superior hold. 4" would work, but it seems like you'd max out the suitability of the VM100 at about 3" or 100mm jaws. Personally, I would also use the VM120 for large platters and larger bowls (>=14"), but that's just my comfort zone and not based on science. Maybe it's time for a John Lucas study, (assuming he can take time away from his new Hollywood career for a little while).
 
Raif Harik said:
It seems to me that the only advantage of the larger chuck is that it can probably take bigger jaws but unless you are doing really large crazy pieces when would you need jaws that large? Further if you are turning crazy large pieces you are probably drilling down a face plate.
Click to expand...

Raif, in general I agree with you, but there are times when size does matter. I have three VM100 chucks and one VM120 chuck, I use the VM120 chuck probably about twice a month, for the rest of the time the VM100 and the vast array of jaws I have collected over the last decade or so, see me satisfied.

This is one of the heavier and larger pieces of timber I've turned on my lathe. I used the VM120 chuck and the largest faceplate ring Vicmarc have. Compared to a stand alone face plate, it appears to be quite a flimsy bit of equipment, but it is surprisingly rigid. From memory I made five bowls out of this blank.

Once I start coring and especially with very green/wet wood which translates to very heavy wood, I've found I need a decent grip on the tenon, as well as a decent tenon. The depth of the VM120 jaws as well as their dovetail angle, ensures a reasonably strong grip that doesn't let loose too easily. The below pictures show the rough blank, then the tenon made to fit the same jaws, whereby I started coring out the blank; fun day with free showers.

The other reason I really like my VM120 chuck, is the ability to have very wide circular gripping of a very small tenon under a platter or a very wide and shallow platter like bowl. Over time, I've slowly made my tenons smaller and smaller, depth wise that is. These days most of my final tenons on dry wood are around 2mm in height/depth, and I need an almost perfect circle of grip with a sanded, oiled, finished tenon, that is strong enough to hold the blank while I do the inner of the bowl. The larger diameter jaw sets available on the VM120 chucks fit the bill very well.

2436_690mm_Diagonal_Blank_web.jpg IMG_20191021_161507_Web.jpg
 
So what I've heard is the 120 is better a) for some activities e.g coreing or very large and/or wet wood and b) the jaws for a 120 may be deeper and the dovetail a different angle. Idk, I don't have a 120.
So certainly if you do these things one should have a 120. But why is that the norm? I mean it sounds/feels to me like 80/20 in favor of the smaller chuck. One reason this is relevant is the 100 is cheaper and you only want to build up a collection of jaws in the one size if you can help it.
Perhaps the question I should be asking is "when and why do you need a large tenon. How do you know?"
 
I have one VM150 and two VM120 chucks - plus 2 complete sets of dovetail jaws in every size they make - they all get used.

7", 8" & 9" jaws are good for -
1) roughing out large green bowls - initial turning is with a faceplate and after blank is round and bottom flat I make a tenon as big as will fit on the bottom - why a 9" tenon? no worries about holding power when hollowing but biggest benefit is when dry and ready for finish turning a large tenon often has enough size that it can be made round again with enough wood to turn a foot and house a mortise so I don't lose the 1/4 of depth of the tenon in the finished bowl
2) when dry the easiest way to mount the now dry rough bowl to reshape the outside/foot is to make a mortise in the interior - very large jaws let you make the mortise in the walls not just the bottom which on deep walled bowls can be a problem

for times when the vm jaws (85mm or 105mm) are not the perfect size - I use one of my OneWay stronghold chucks

if I was to get anything else to add to the chuck inventory it would be another 120 body or two - no big deal to change jaws but sometimes it seems to be a constant interruption to the work-flow
 
We all have different experiences, different styles, different things we turn, and different ways to get there. Having two size chucks is sorta like why have a pickup and a sedan, or why not hit every nail with a sledge? OK for some, not for everyone.

I have 3 VM120s and 2 VM100s (and 2 older Novas). I pick up a chuck based on what jaws I need. This is influenced by what jaws happen to be on the chucks, and is limited by what I happen to own - the 3" jaws for the 100 fall between the "standard" and 4" jaws for the 120.

The one significant difference (for me) is the "standard" jaws on the 100 are smaller (about 2") than the "standard" 120 jaws (about 2.5"). And that makes a huge difference for some of my work - the 120s are often too big and the 100s are just right. This is probably why I bought my first 100 (after a couple 120s).
 
Aha, now the cases are adding up. Erik's explanation does explain quite a bit actually. I've only just started twice turning my bowls. In fact I have a couple roughed out ones in paper bags and that's as far as I've gotten. So the large jaws do make a lot of sense to facilitate the second turn. I've probably screwed up the rough bowls as a result, but I'll figure something out.
I totally understand having multiple chucks. That part I get 🙂. I just don't want to pay so much for them. That and I was curious. Often when I don't understand something it's a good indicator that I'm doing something wrong. So I wanted to know what I was screwing up this time. Luckily damage is not too bad, I may just have to use the default jaws for my 100 to turn a pretty big bowl. I'll be careful.
I have the one 100 with the 4" and a new set of shark jaws which I love. I guess the next chuck I buy should probably be the 120.
I guess if someone can explain why a large tenon on a platter is better that would be helpful. I'm drying out some 14" platter blanks now.
Thanks for the help as always
Raif
 
Raif Harik said:
So what I've heard is the 120 is better a) for some activities e.g coreing or very large and/or wet wood and b) the jaws for a 120 may be deeper and the dovetail a different angle. Idk, I don't have a 120.
So certainly if you do these things one should have a 120. But why is that the norm? I mean it sounds/feels to me like 80/20 in favor of the smaller chuck. One reason this is relevant is the 100 is cheaper and you only want to build up a collection of jaws in the one size if you can help it.
Perhaps the question I should be asking is "when and why do you need a large tenon. How do you know?"
Click to expand...
A good rule of thumb is your tenon should be 40% of the diameter of the piece. If I core a bowl, I may even use a tenon at 50%. On platters I would use a recess of 70-80% but that is more for looks. You could go smaller on a platter than 40% and be alright.
 
Platters tend to be larger than bowls (ok, not every platter is larger than any bowl - but in general a useful size is going to be on the bigger side). Also, for stability, a platter tends to have a larger foot/base. Also, platters are often turned from thinner stock - often you're making a platter from something maybe only 2" thick. So conservation of the wood is probably important.
So, a lot of the time platters are turned with a recess rather than a tenon - so the exterior of the recess becomes the foot.
Bigger jaws hold better (more surface area around the circumference), and more closely match the eventual platter foot. So it becomes a logical choice.
Nothing says you couldn't turn a 12" platter with a 2" or 3" tenon. But events usually stack up such that a larger recess is a more natural choice.
 
One thing I noticed recently when using my new threading jig is how much of a liability a heavy chuck can be when used for this particular application.
I’m never going to be threading anything large so I’ve decided that I’m going to buy another of the very diminutive Record Power SC2 Chucks. They are very inexpensive and I’ve come to realise, more than adequate for box turning. At least in the sizes I make.

If I ever turned really big stuff I’d be trying to find a 6” chuck as most of the “big” chucks on the market aren’t that much bigger than the standard 4” ones?
No, I lied. My lathe wouldn’t handle a 6” chuck. But I’m sure many of you have lathes that could easily cope with a 6”?
 
To the newer woodturners of the world-

One does not  need umpteen chucks. One  wants umpteen chucks. One or two chucks, depending on the projects (large and small), and 60-90 seconds of patience to twist 8 little screws, will do you just fine as you explore and grow. Over time you will realize what it is you need and want (maybe that will be a handful of different chucks all with a different set of jaws, but that's a lot of coin to save a minute or two of time), but don't rush into spending a thousand dollars for a shelf full of chucks. You probably aren't doing production work where time is money.
 
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